# Probe 4: Regional Stepwise Addition

Cumulative build-up from EBA-49 → full 140, both control specs.

## Simple (4 ctrls)

| Step | Z₁ Coef | Z₁ SE | Z₁ p-val | R² | N | Countries |
|------|---------|-------|----------|----|---|-----------|
| EBA-49 | 33.09* | 17.49 | 0.059 | 0.352 | 1448 | 48 |
| + SSA-20 (=69) | 5.66 | 16.62 | 0.733 | 0.275 | 1979 | 68 |
| + EU-10 | 16.26 | 16.73 | 0.331 | 0.220 | 2216 | 78 |
| + LatAm | 19.09 | 15.48 | 0.218 | 0.199 | 2496 | 88 |
| + MENA/C.Asia | 13.19 | 11.88 | 0.267 | 0.299 | 2909 | 103 |
| + S/SE Asia | 10.06 | 11.69 | 0.390 | 0.271 | 3146 | 112 |
| + E.Eur/Caucasus | 9.58 | 11.97 | 0.423 | 0.261 | 3342 | 121 |
| + SSA-ext | 17.37 | 12.41 | 0.162 | 0.219 | 3840 | 138 |
| + Other (=140) | 23.21* | 12.62 | 0.066 | 0.224 | 3869 | 139 |

## Full (7 ctrls)

| Step | Z₁ Coef | Z₁ SE | Z₁ p-val | R² | N | Countries |
|------|---------|-------|----------|----|---|-----------|
| EBA-49 | 2.77 | 19.71 | 0.888 | 0.523 | 938 | 47 |
| + SSA-20 (=69) | 15.26 | 21.74 | 0.483 | 0.395 | 1316 | 66 |
| + EU-10 | 12.63 | 22.13 | 0.568 | 0.308 | 1516 | 76 |
| + LatAm | 15.92 | 20.85 | 0.445 | 0.274 | 1685 | 86 |
| + MENA/C.Asia | 27.73 | 17.28 | 0.109 | 0.367 | 1982 | 101 |
| + S/SE Asia | 17.45 | 17.14 | 0.309 | 0.312 | 2162 | 110 |
| + E.Eur/Caucasus | 13.96 | 17.13 | 0.415 | 0.293 | 2336 | 119 |
| + SSA-ext | 17.46 | 16.23 | 0.282 | 0.281 | 2676 | 136 |
| + Other (=140) | 19.03 | 16.12 | 0.238 | 0.284 | 2695 | 137 |

